Create safe helper for LLVMSetDLLStorageClass

Author: oli-obk

compiler/rustc_codegen_llvm/src/callee.rs

@@ -66,9 +66,7 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
             // LLVM will prefix the name with `__imp_`. Ideally, we'd like the
             // existing logic below to set the Storage Class, but it has an
             // exemption for MinGW for backwards compatibility.
-            unsafe {
-                llvm::LLVMSetDLLStorageClass(llfn, llvm::DLLStorageClass::DllImport);
-            }
+            llvm::set_dllimport_storage_class(llfn);
             llfn
         } else {
             cx.declare_fn(sym, fn_abi, Some(instance))
@@ -150,7 +148,7 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
                 && library.kind.is_dllimport()
                 && !matches!(tcx.sess.target.env.as_ref(), "gnu" | "uclibc")
             {
-                llvm::LLVMSetDLLStorageClass(llfn, llvm::DLLStorageClass::DllImport);
+                llvm::set_dllimport_storage_class(llfn);
             }
 
             if cx.should_assume_dso_local(llfn, true) {

compiler/rustc_codegen_llvm/src/consts.rs

@@ -375,9 +375,7 @@ impl<'ll> CodegenCx<'ll, '_> {
                 // is actually present in the current crate. We can find out via the
                 // is_codegened_item query.
                 if !self.tcx.is_codegened_item(def_id) {
-                    unsafe {
-                        llvm::LLVMSetDLLStorageClass(g, llvm::DLLStorageClass::DllImport);
-                    }
+                    llvm::set_dllimport_storage_class(g);
                 }
             }
         }
@@ -387,9 +385,7 @@ impl<'ll> CodegenCx<'ll, '_> {
             && library.kind.is_dllimport()
         {
             // For foreign (native) libs we know the exact storage type to use.
-            unsafe {
-                llvm::LLVMSetDLLStorageClass(g, llvm::DLLStorageClass::DllImport);
-            }
+            llvm::set_dllimport_storage_class(g);
         }
 
         self.instances.borrow_mut().insert(instance, g);

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -403,3 +403,9 @@ pub(crate) fn add_module_flag_str(
         );
     }
 }
+
+pub(crate) fn set_dllimport_storage_class<'ll>(v: &'ll Value) {
+    unsafe {
+        LLVMSetDLLStorageClass(v, DLLStorageClass::DllImport);
+    }
+}